A multicentre, double-blind, randomised, placebo controlled study to determine the efficacy and tolerability of OXN PR for the treatment of severe Parkinson's disease associated pain

To demonstrate superiority of OXN PR compared to placebo with respect to analgesic efficacy in subjects with chronic severe pain associated with Parkinson's disease (PD), as assessed by averaged 24 hour pain scores collected for 7 days prior to the clinic visits.